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Tiles for Baking stones?

December 6, 2005 - 4:27am

timtune

Tiles for Baking stones?

Hi,

I heard that unglazed quarry tiles can be used to substitute for pizza baking stones.
Are unglazed quarry tiles granite tiles?
Can ceramic tiles be used instead? (though ceramic is more of a heat insulator)

No I'm pretty sure it's not granite that you should use. I think the quarry tiles referred to are those which a heavy, usually red, flooring tiles - I think they are ceramic in composition, but are a particualr type of stoneware so are durable. Granite wouldn't find a home in my oven - it is radioactive and if some dust from it gets in your food then it will probably contain some alpha particle emitting chemicals, not what you want if you want to 'live long and prosper'! PLus the fact it will probably crack given the crystalline nature of it and the flaws it will contain.

Some forms of granite used for kitchen counter-tops seem to emit rather high quantities of Radon, connected with lung cancers. However, that is in ADDITION to granite's own radioactivity, which is no more dangerous than lying on a beach, or playing with your kids in a sand-box...Sand and sandstone and other sedimentary rocks such as granite are all slightly radioactive (...basically, so is everything else, too. It's just a matter of degree. Nothing to worry about, anyway!)

I've read health newsletters that suggested pregnant women try to spend as little time as possible in the kitchen if they have granite counter-tops. Personally, I would suggest getting the Radon levels checked, just in case it's the "bad stuff".

Oh my gosh! Someone posted a reference to back up their statements! That rarely happens on the internet. I am so impressed!

After reading the article, one sentence stands out: "Allegations that granite countertops may emit dangerous levels of radon and radiation have been raised periodically over the past decade, mostly by makers and distributors of competing countertop materials."

I tend to be a skeptic about many things, but in this case, I'll take my chances. ;) Maybe the radiation will make my bread taste better.

Some experts claim that about 5% of granite slabs might be of the "naughty, Radon-emitting kind" but no-one knows. Can you imagine the absolutely TINY number of samples that have been tested?

Banks and other prosperous companies have been using granite to front their buildings and line their counters for centuries and office workers don't seem to have above-average cancer risks, despite prolonged exposure for hours a day.

It's just a simple fact that every rock and grain of sand is slightly radioactive (as is virtually everything we touch and see in our daily lives). Is it worth worrying about? Not unless it's MANY times higher than the "background radiation" that we are all exposed to, just by living on Earth.

I've tried to read all posts and like to add a question which may be a solution

for all baking tile issues as well.

In The Netherlands (Europe) we have a company that supplies all major baking oven producers in Europe with a plate that is heat resistant up to 450 Celsius and applies to the very strict German Food regulations.

If it were possible to use these plates in a (relatively) small size would this be o solution for all baking tile problems.

Before answering please check out: fydro.nl click on the 'english' button and look for your self.

i am a tile setter and promise this is the real scoop. if you look in 'bread bakers apprentice' there is a pic of thier oven with tiles on the rack. these are the same 'unglazed quarry tiles' - different color though. they come in 6"x6" or 8"x8", mine are 6". i personally have not had one break yet but i am sure it is possible over time. i have put parchment on the tiles and also baked directly on the tiles. i use 6 full tiles 5 half tiles and 1 1/4 tile and stack them all together for a good size deck. if you have a Dal-tile (national company) you can get them there. if not look on craigslist for a tile setter and ask him where to get them in your area.

in sw france where i live most roofs are with half circular red terracota tiles same material as plant pots. I put one in oven to heat at same time as warming oven and use another lined with Ali foil to help form loaf. after rising transfer to hot tile and cook.
I have also cooked in flower pots as with Paul Hollywoods (100 great breads)pepper and onion flowerpot bread. That looks great for a BBQ.
manxman

Manxman.... This is a great idea. One tile works as a "couche", and the other hot tile would help maintain the shape while baking. If I used parchment under the rising loaves, I could slide it into the red-hot oven tile? I will look for some hard terracota roof tiles. Interesting "substitution" for the baking stone that I normally use.

Quarry tiles are genreally considered safe to bake on. The concern is with glazed tiles which may contain and may release lead in your oven - not a good thing!

Unglazed quarry tiles are thick and are made of fired clay, basically as it comes from the ground. Thus it has other things in it besides clay.

Ceramic tiles are generally thinner and but stronger. This is because they are made from "refined" clay in a powdered form. The end result is a more uniform tile, thus it is stronger.

Both types are made entirely from earth materials, and if unglazed, should be fine for baking on. Do not bake on glazed tiles!!!!! Particularly if from a foreign source. If in doubt contact the manufacturer.

Notable Exception: I am aware of one handmade baking stone on the market that is glazed. There likely are others.

But one of the advantages of baking stones and quarry tiles is that they are unglazed and thus allow moisture to pass out of the bread bottom, for better crisping. So, at least for bread and pizza baking, I don't get the glazed stone thing.

I used quarry tiles with good success until they cracked into smaller and smaller pieces from using steam in my gas oven. I have switched to rectangular bread tiles/pizza stones. If you shop around, they can be had for about $13-15 a piece, I use two, one under the bread, the other above. Works great and I no longer have to assemble a jigsaw puzzle before baking.

I generally heat my stones for an hour at 500 degrees, high as my oven will go, before baking. I get great crust and crumb.

I've been thinking about adding a baking stone above the bread. Can you tell me the difference you think it makes in your breads? I'm generally happy with the color and crispness of my crusts but have trouble achieving ears and my crust doesn't crack as it cools. (neither of which is a problem is I bake in a dutch oven so I'm thinking it's the condition of the oven and not the formulation of the bread).

now good stores have a tile slab, one peice,!! even have a slab for each side & the back of your oven,, that makes it somewhat of a hearthoven. takes alittle longer to heat ,Isuppose. what a difference in performance, think about it. hotbred

I've used unglazed quarry tiles for years in my oven--I just leave them there all the time. One or two a year might break, but at $1 or less each at home improvement stores, they're easy to replace. Much of the time I slide my bread in on parchment paper, but I've often baked directly on them with fine results.

Much cheaper than a larger, more "official" pizza stone or such, and I'd guess the results are similar.

I am sure Lowe's has them. I bought one at Home Depot. Go to the isle that has tiles. The one I liked was glazed but I purchased it anyway. I just put the glazed side down and bake on the rough side. Also, the tile was 16 x 16 inches. Home Depot will cut it for you. I needed two inches taken off of one side so that it would fit into my oven.

I was just at lowes yesterday, and at least the lowes HERE did NOT have the unglazed tiles. the guy knew what I meant when I asked, but didn't carry them. he could order them but that was like 11 square feet coverage of them, in 8" tiles. meh.

look in the phone book for tile suppliers, if you have a dal-tile nearby its garanteed they have em or call a tile installer, he'll know who is selling commercial tile in town. ive used them for years, they are great. as a matter of fact if you look at the kitchen pics in bread bakers apprentice you can see them in peters oven.

Metropolitan Ceramics. They are red tiles, almost like saltillo tiles. Mine came in 6x6 size. I bought a whole box at the suggestion of others who notes they were so inexpensive that if one breaks it could be immedicately replaced. I've enjoyed using them. They are unglazed and made in the U.S.

Look under unglazed ceramic tiles if quarry is too hard to find. Good luck!

Having worked for a company that made pottery firing supplies and firebrick, among other refractory products, I can report that they are not necessarily food safe. Since they are industrial products you should be able to get a Material Safety Data Sheet (MSDS) for them, but then again refractory producers don't usually do food safety testing except for certain food-oven liners.

I applaud the thrift and frugality that is displayed on this group, but I have also seen the results of long-term industrial poisoning and they are not pretty. Please do me a favor and buy a stone from a supplier that will provide a food-safe certification.

Searching my local area for unglazed quarry tile, without luck. I finally broke down and bought a FibraMent stone. It's 17 1/2" x 14 3/8", a whopping 3/4" thick, and comes with a 10-year warranty and free shipping.
Well worth the $46, IMHO. I figure my time alone is worth that much.Fibrament Homepage
-Joe

I read all the opinions presented in this site and my head was sent twirling. I decided that after seeing the tremendous oven-spring a simple round loaf of wheat bread got on my pizza stone (now broken due to steam) I should look into a larger, more robust piece of masonry.

I couldn't wrap my brain around anything that wasn't a large slab (IE: quarry tiles, bricks, very small rocks) so my choices seemed to be kiln-bottoms or Firbrament. I'm pleased to say I placed my order on Fibrament's WWW site very early on a Thursday morning and received my stone mid-afternoon Friday using standard shipping. (keep in mind I work by O'Hare airport in Chicago and the Fibrament company is located on Chicago's south side but it still was GREAT turnaround)

After I seasoned the "stone" I whipped up my second attempt at FloydM's pain sur poolish and made two of the ugliest shaped loaves I've ever seen with some WONDERFUL oven spring, crust, and crumb. The ugly part was my fault as my dough stuck to my cutting board (AKA fake Peel) in spite of the corn meal I had sprinkled down to avoid such an outcome.

Bottom line, my oven fits the $66 stone and I consider it money well spent. My bread is turning out markedly better looking and I'm enjoying the "brick oven" feel without the expense of building out one.

This post and all my others are just my $.02. Thanks to the FreshLoaf community for turning me back on to a hobby that my mother started me on when I was a wee little lad with a tiny little loaf pan making bread with her.

Joe, Thanks for the link. I just bought the same stone you have. I can't wait to get it! I've been using a round pizza stone (also 3/4" thick) for nearly 10 years. Great for boules, torpedo shaped breads but not so great for the baguettes.

I have the unglazed red quarry tiles and have put them on the bottom rack in the oven. Should I be placing the bread directly on parchment paper on the tiles and cook the bread on the bottom shelf? Or, should I put the tiles on the center shelf and cook the bread there?

If I place the bread in a tin, should I put the tin directly on the tiles? And on what shelf should I be cooking the bread in the tin?

Slate was used tradtitionally here in UK for old fashioned wood fired ovens in older houses - the floor is of slate, walls of brick. My dream is to have a thatched house with inglenook and faggot oven - which I would use, for bread.
So if its good enough to use slate in a traditional oven, it should be good enough for a modern one.
Andrew

I bought a 12"*12* slate tile in the gardening section of B+Q (diy store). Its 1" thick and quite heavy. However this was rectified the first time I used it. Cracked right down the centre, making it easier to take off the rack when I'm not making pizza.

You can get them at almost every hardware store, for example, Home Depot. These come at US $11 a box. Splurge on one or 2 boxes, depending on your oven size, and lay as many whole layers that you can. The tile manufacturer for Home Depot is in the US, and states that the tiles are food-safe.

The extra-thick combined tile layers has improved the quality of my breads dramatically. Even baking/browning, constant temperature, etc, are just a few of the benefits of using this baking tiles. Forget the fibrament. Get 1 or 2 boxes of white kitchen tiles (if unglazed can't be found, get the glazed, and lay the tiles with unglazed backside up).

BTW operating an oven with ceramic tiles is like operating a hearth oven - - it needs to be preheated with ample time. In my case, I need a 1-hour pre-heat. The lengthy but proper tiles and pre-heat are worth it, because I now feel like I have a commercial Blodgett!!

I searched all over town for big unglazed quarry tiles and could not find any, so I bought a 16 x 16 piece of slate that fits my oven perfectly. So far, it has worked well at getting those crunchy crusts, after it is fully heated. I usually put the loaves in on parchment and just leave it in place, because then I don't have to worry about bits of whatever on the surface of the slate.

I did make a mistake in allowing the stone to get very wet, and ended up with some flaking next time I used it at high heat. i had washed it and left it outside to dry in the sun, then forgot it during a downpour, so it got soaked. I put it in the oven on low heat for what I thought was plenty of time to dry it, but apparently not long enough.

A good pizza stone or quarry tile would be better because it would be thicker and would hold more heat longer. But for now the slate is doing a fine job. And it only cost about $5, so I figure I can bumble my way through a lot of these before I can justify $40 for a commercial stone.

Quarry tiles are not the same as other unglazed tiles. There could still be some gnarly stuff in your tiles if you use regular tile. Unglazed quarry tiles are made from lead-free, natural clay. If you seem them in your local store, they look like terra cotta (but they aren't... terra cotta often does contain lead). At the Home Despot, the brand they usually have is called "Saltillo." It even says "lead-free" on the box. But they do carry glazed ones too... you definitely don't want those. Unglazed.

They are dirt cheap. IMHO, buy the whole box so you can replace the ones that crack. I got 1 ft square tiles and cut them to fit with about 2 in room around the sides. Works like a charm. You might also find it useful to bake them for a while before using them the first time, slowly increasing the heat to maximum. That will bake out the last of the moisture and minimize the amount of broken tiles.

I also found it useful to scrub the tiles with baking soda and water before the first use. That got all the dust off and made them nice and clean.

I am new to pizza baking and have a few questions regarding my choice of stones. Presently I have a cheap pizza stone and aquired some quarry tiles for future use. I would appreciate any answers to the following questions:

What is the gray inner core of a Saltillo quarry tile (visible when cut)?

I don't know what the core of your tiles is. My tiles are solid ceramic.

I've never heard of a pizza stone containing asbestos. That would be a bad idea.

Best heat? As hot as possible safely. I do 550, the max my oven can handle. This guy even rigged his oven to be able to go over 800 degrees. I would not recommend doing that, but you get the point that the hotter, the better.

Tiles above aren't necessary, but if you have extra you might as well put them there. The air in your oven rushes out when you open it and the oven cools off quite a bit. When you've got a bunch of ceramic tiles in there radiating heat, like in a sauna, it stays much hotter.

I've never used steam with pizza. Yes, one should be very careful when handling water near hot tiles. I always get my water boiling in the tea kettle before pouring it into a cast iron pan when baking French bread. That way if I accidentally spill some on a tile (which I am very careful not to), the temperature difference is only... 300 degrees instead of around 450.

The gray inner core of a Saltillo Quarry (the name of the Quarry) tile is most likely created in the firing process of the ceramic tile. When the tile reaches the optimum temperature in the kiln, it can happen that oxygen is cut off, forcing elements like iron to the surface thus leaving core or middle lighter in color. This is a natural process in ceramic firing. The next question is naturally what other goodies have been pulled to the surface. I've been Google-ing around but have not yet found the Chemical makeup of Saltillo Quarry clay or even if it has been aproved for food. Anyone have luck or suggestions? Mini Oven

Floydm and Sphealey, Thanks for the good advice and input regarding my newbie questions. Having a two year old, I am very cautious about any health hazards. Since the closure of the best NY style pizzaria in my neighborhood, We started to make our own personal pizzas and garlic knots on my cheap, thin pizza stone. My daughter loves making her own and seeing the results, good family time. Since I havn't been able to find any specification or MSD Sheets on the quality stones or tiles, I was wondering if CAST IRON has worked for anyone. I know that it has great heat retention qualities and can be cleaned easily, if seasoned properly. I have read many comments about porous surfaces drawing moisture, but do not suspect any moisture would rest on anything of that temperature. Any comments, advice?

My mother did a great deal of baking in her cast iron skillets. Cakes and cornbread mostly, but a few other things as well. If you choose to use cast iron, use it as much as you can so that you become familiar with the results.

Soap box time. I think we are over analyzing things. We need to not spend so much time on what to acquire, but to utilize what we already have or have access to. Find somehting that works, and stick with so that we become proficient at using what we already have. Granted, some purchases may have to be made, but whether it is cast iron, ceramic tiles or whatever, use it and have fun doing it. The learning will come automatically! OK, stepping off my soap box now.

I like using a cast iron dutch oven for boules. I also use cast iron skillet for baking pull apart rolls. Both work great. I also have a round cast iron griddle type pan that I've used for pizza...however, it was not as good as my baking stone.

Some day I would love to do a complete Cooking for Engineers-style investigation of the whole question of baking surfaces. I have read many theories and tried some experiements myself, but I am not convinced that we amateur bakers really know what is going on when the dough hits the flat hot part.

But until then, my thought would be that cast iron has substantially different heat transfer properties than ceramic, and I suspect it would not work well. Plus you would be handling a huge chunk of cast iron.

King Arthur is now carrying a reasonably-priced 14x16 pizza stone in addition to the Hearthstone [1] and I am sure their customer service would talk to you about food safety. Why don't you look at that one?

sPh

[1] The Hearthstone works very well for me when I preheat it to 525 using the convect setting, but it is very large, heavy, and expensive.

works superbly. In my last oven - which was larger than my present one - I used a Le Creuset crêpe pan which gave excellent results - super heat retention, even heat distribution and extremely good oven spring! I felt it was the nearest I'd get to an Aga cooker (http://www.aga-rayburn.co.uk/57.htm) which of course uses cast iron throughout its ovens.

Unfortunately it doesn't fit in my present oven and I've still to find a piece that fits with room for heat to circulate round one, but when I do... At present I'm using a pizza stone - good, but not as good.

So if you can find a piece of cast iron the right size, and about the thickness of a crêpe pan, grab it. You won't be dissappointed. (Probably mild steel would work well too.)

The Hearthkit oven insert works exceptionally well for me (its expensive, but I'm lucky, mine was a gift). The only problem is the weight and though they state that it can remain in the oven at all times, I found that cumbersome and take it out when not in use. But that said, the crust and crumb are the best! But I've wondered if by putting quarry tiles up against the sides of the oven and a pizza stone on the shelf you might be able to mimick the effect.

Yeah, the price of the Hearthkit drove me to research the thermodynamics of what's going on in the grill and find other options. My HomeDepots don't carry ANY unglazed quarry tiles that I could find (maybe due to post-Katrina demand) so I went with a box of 6 inch slate tiles.

3 stacked against either side and 3 across the back, and 2 12" on bottom and 2 12" on top warming rack. Homemade Napoletano pie comes out fabulous.

The ones on the sides must have had some moisture because some popped apart. The cornichone (outer crust) came out a little darker than I wanted on some after adding the 2 12" tiles on top so I might go with 1 for my next pizza grill blowout.

Other than that, great heat retention with a 30 second lid lift for load/unload of pie onto round stone on top of 12" slates. 550-600 degrees re-achieved in 5 minutes after unload.

It will depend of course on the arrangements and efficiency of your burners and where they are located and the general heat holding cpability of the grill box as it is alone.

When i initially tried the cheap Home Deopt route on for baking stones, i went to Home Depot and asked for unglazed tiles and was sold one large slate tile. I took it to my cousin's house, with a quick electic oven, and tried it. The tile, more or less, exploded during the preheat which was an admittedly fast one. It was going to 500 degrees in five mins. No damage to people or equipment. Just lots o' embarassment.

I went back to Home Depot, after finding this site and reading this blog, and specifically requested unglazed quarry tiles. After a bit of looking, the sales associate and i found them. There were 4x4 inch red tiles. The tag on the shelf said specifically "unglazed quarry tiles" and they looked like red terracotta tiles. It reminded me of a flower pot. I bought six of these, at 33 cents a piece, and they have been great. No explosions. I have an older gas oven which heats much more slowly than my cousin's electric one and i think this helps. The money saving is certainly worth the initial explosion.

For gas ovens: Unglazed quarry tiles should not be placed on any rack in a gas oven, but rather on the floor of the oven.

For electric ovens: Place the oven rack on the lowest position and line it with the unglazed quarry tiles.

Measure your oven and leave about an inch border around the edge of the floor of the oven for air circulation.

Instead of local home development centers like Home Depot, check out your local ceramic tile suppliers for the unglazed quarry tiles.

Look for tiles that are just slightly less than 1/2 inch thick. Tiles thicker than that take too long to heat up, and thinner tiles may crack from the intense heat.

Preheat oven to 500 degrees for 1 hour before baking is the standard rule.

My gas oven only goes to 500 degrees, but heats up to that temperature in about 20-25 minutes (monitored with an oven thermometer placed on a rack about mid oven), so I typically put the pizza into the oven at about 30 minutes, and bake for about 18 minutes, i.e. when the crust is brown and the top sizzling!

I've been using 6" square quarry tiles (1/2" thick) from ColorTile on the middle shelf of the oven which gives great results. Using the middle shelf keeps the tiles from being too close to the heating elements which can lead to cracking of the tiles from thermal stress. I also think you get better heat distribution.

I had 2 tiles of the 6" tiles cut in half which allowed me to tile the 15" x 18" shelf while allowing about an inch all the way around for air circulation. I also have a 12" square quarry tile that is thicker (3/4") that I use when I'm doing a single large round loaf that does even better for giving oven spring. I put a shallow pan on the lower shelf where I put hot water before and during the first few minutes of baking. It is important not to put water on the tiles or directly on the bottom of the oven. Right now I am looking for thicker tiles to cover the shelf and place on the sides, as I am sure the results will be much better.

I leave my tiles in the oven all the time, no matter what I'm cooking. They are pretty cheap at the home stores and I think I've only had to replace one in the last eight years. Be sure you leave a few inches of clearance on the sides for good air circulation in the oven.

My husband just bought me a fibrament stone--I'm a beginning baker--and I'm doing the initial heating of it now. The fumes coming out of it make me very concerned, we've worked hard to make our home as non-toxic as possible and this product seems like it could be very toxic, both in the fumes it produces and in contact with our food. I read the company's statement about how anybody wanting to know the composition of the stone would have to buy the company and now I am incensed. I'm still waiting to hear back from them, but does anybody know of any hard data on the composition of the stone? I'm ready to hurl it back at the company, performance be damned.

Keep in mind that I don't have a Fibrament stone; I'm just pointing you to some other TFL members' experiences. Since the Fibrament stones are designed for use in ovens (the food prep kind, not the ore smelter kind), they are NSF rated. I suspect that once you get through the initial drying/seasoning cycle, you probably won't notice any other odors. Refractory materials need to be very stable, even at high temperatures, so the probability that a refractory material which is already non-toxic (remember that NSF rating) off-gassing toxins at normal baking temperatures is vanishingly small. You might just as well worry about aluminum uptake in trace quantities from aluminum utensils. sPh, a frequent TFL poster has real-life experience in the refractory industry and can speak about it more knowledgeably than can I.

All that said, if you don't feel comfortable with the stone, send it back.

However, once you and the stone each cool off, you may find that you get along together very well.

The fumes did start to go away even as the temp got higher, and while I still think it's rather inconsiderate of the company to dismiss questions about the stone composition they way they do on the site (yes, I realize they were trying to be funny), I'm starting to think that now that the stone is fully dried, I won't get any more fumes.

I'm glad that they're NSF rated, but I still maintain enough skepticism to question the rating, especially in the face of what my senses are telling me. Like Teflon, for example, which is also intended for culinary use, but over the long term, it's a health threat and an environmental threat. Which is why I was trying to find actual composition info. on the Fibrament stones. I'm hoping they'll write or call back as respectfully as others have indicated and that I can get some more concrete info.

Yes, I followed the instructions. As I recall, there weren't fumes the 2nd time I heated it (or hardly any), but there were fumes the 1st time. Plenty. I just wish I'd done it when it was warm and I could open the windows!

Unglazed Terra Cotta (such as you find for flower pots or European roof tiles) are simply clay, and are just fine for baking. Fire Brick, however, which is used for kilns and for woodburning stoves, have alumina in them and are not suitable for use in baking. There are also stone slabs that are used for grilling meats, fish, veggis on the grill. Here in France, food preparation on these stones is referred to as "Plancha". I have one such slab (30cm x 30cm) and have been using it for many years. I believe that it is soapstone, but I won't swear by it. These are also excellent for pizza stones—even in a lidded grill. I believe that Weber Grills offer such a pizza stone for their grills.

Well, as far as I have read, alumina is not certified for culinary use. One should not bake bread or barbecue or cook food in woodburning heating stoves, for example, that are lined with firebrick. I cannot tell you why, only that I have read in various sources that it is unadvisable. There are certainly some chemists among us!?!

I used natural granite stone which letf over from house repair put in my oven, and sometimes I used ceramic tray that came with microwave oven too. Both work out good. I don't know if any dangerous chemical in it.

Our first attempt to cook pizza in our gas BBQ last night: used two terracotta (quarry) tiles- one about 12 inches square and the other about 10 inches square. The larger one, which I had previously used in the "ordinary" oven in our house, was fine. The other, smaller one, first cracked, which we ignored, then exploded loudly and dramatically. Lucky the lid was on!! The force of the explosion curved the bbq grid downwards. Shattered into many pieces and bits of grit. The pizzas cooked well though. However, we are rethinking our strategy on this!! The oven temperature wasn't particularly hot: about 350 degrees Celsius. Maybe there was too much direct heat under the tile, which heated it unevenly. It was pretty scary. They were both old tiles left over from our house renovation 20 years ago,but in good condition- and given that tiles can last hundreds / thousands of years, I don't think age was the problem..

floor tiles aren't designed for repeated heating, and so you often find air bubbles inside, especially in quarry tile and saltillo tiles. if the tiles are exposed to moisture, the formation of steam inside those bubbles can easily blow the tile apart; and even if they're dry, given enough sudden heat, the same thing can happen with the trapped air. a lot of people use tiles very successfully, but accidents clearly do happen ...

after all, people have been eating off porcelain (and chewing with it) for centuries. what i would be concerned about, however, it porcelain's low resistance to thermal shock, which means that if you're spraying loaves in the oven and some of that water hits hot porcelain, there's a higher likelihood of cracking than with other materials.

I just got home from doing errands, one of which was hitting up Lowes and Home Depot.

asking the guy at Lowes, he seemed to know *exactly* what I was referring to as "unglazed quarry tiles", and said that they did not carry that anymore. that they used to, but don't now.

he said he could special order it though, and showed me a page in his product catalog with it, and he called in and checked the price for it. said they were something around 22 bucks for a box that'd cover 11 square feet. pretty sure that was for 8" tiles.

interestingly for my experience, *BOTH* people I talked to, knew exactly what it was, said they used to carry it, and that they didn't know why they didn't still carry it. I explained what it was for, and neither said "oh no that sounds dangerous and/or poisonous!" in fact they both sounded like they had heard of that before, or at least like they thought it sounded reasonable.

so is this a correct summary of things?

All tiles need to be, at first, heated slowly to purge moisture from the inside of the tile, spending some time heating it at lower, but incrementally higher temperatures working up to the desired temperatures.

"Unglazed Quarry Tile": (as in, the specific item of "quarry tile" that is unglazed) is the ideal, foodsafe and cheap.

"Slate": foodsafe(its pure cut stone, afterall, right?) but more fragile, and needs to be heated gradually at first, or when exposed to water (I assume not counting the water IN the bread?) to dry it out more meticulously/slowly than quarry tiles. not as cheap.

"Porcelain": PROBABLY foodsafe? very vulnerable to damage from heat variation in use(such as water exposure)

I was in the tile industry (installations) for 20+yrs While I don't know the answer to this, and I doubt everyone would agree if this is a good idea. I will contend that tiles made for flooring and wall applications are in no way made with food production in mind. They are made to cover floor and walls. I've seen the Fibrament baking stones and plan on getting one soon. For the toime being I use a similar product I received from my father, when the large commercial bakery he worked for was refitting their ovens with baking stones surfaces. They work great, but have warped through the years. They're probably 20 yrs old.

One item I rarely see people mention when it comes to baking stones is soapstone. It is a natural product, easy to cut to size. You can find good deals on tiles and slabs on the internet. It is safe- Iwould never use granite, not for health reasons but because I have seen granite split, crack and pop when heated. Soapstone holds heat very well and has been used a long time for fireplaces, woodstoves...

I bought unglazed 6 x 6 inch tiles at Home Depot on sale for less than $2 each. They are a red color. I use them under a dutch oven for bread and then use a cloche next to that so I can do two loaves at a time. I have had good results with this method.

I was just watching a Good Eats episode (Flat Breads) that had to do with pizza. In it, he describes using the quarry stone instead of an expensive pizza stone. I think it's called an unglazed saltillo tile (Terracotta). They run like a dollar at the hardware store. He used a 12" one.

He used the giant wooden pizza spatula (said they're cheap at a restaurant supply store) and did this.

Put the tile in a cold oven. Turn on the oven to highest temp and let it heat up for half an hour. Then using the wood spatula, he placed it directly on the tile.

He said the tile being porous is key; I think he said something about it absorbing water. He also said they can be left in the oven rather than having to remove it after use. He kept it on the bottom rack of the oven on top of another one, in fact.

I am new to this website and wanted to take a moment thank Floyd and all of the other participants for their vast knowledge and willingness to share. I have learned more in the last few weeks and am looking forward to continuing to explore this wonderful world of bread baking.

I have been using unglazed quarry tile for baking bread over the past several years with no detrimental affects. I purchased them at Color Tile (a local tile distributor in the Chicago area) for $0.69 per 6" x 6" tile. The salesperson knew exactly what I was looking for when I mentioned I needed tiles for lining an oven shelf. I covered two shelves in my home quality electric range for les than $15.00. This included having them cut several tiles so I could cover a larger area. I used 3 1/2 tiles wide by 2 1/2 tiles deep for each shelf. Just make sure ypu leave a gap of at lease 1-2" on all sides for air circulation. I leave the tiles in all of the time (basically too lazy to take them out) at the price of it taking the oven a little longer to preheat. The link below is part of the Julia Child's Master Chef series showing the making of baguettes. They mention using quarry tiles at about 3 minutes 30 seconds into part I.

I decided to google a masonry supply store nearby. I live in a small city and feared there would be none close enough to warrant this venture, but I found one about 10 minutes away. The guys were very easy to talk and I ended up getting a dozen firebricks that were half the thickness of normal brick (i know this is not uncommon, i just don't know the terminology). They fit well in my oven and I did a test run this weekend with pizza and bread. I'm very happy with the results. I built a "house" or a square box out of the brick and got about a 12x18 cooking surface that is covered up. The crust on the bread was fantastic - nice and thick and crispy. The bread cooked faster than usual by about 10 minutes though it did take about 40 minutes for the oven to reach it's max temp. The pizza crust also came out very good and was enjoyed by all.

12 bricks = $16 for me. Your mileage may vary, but it's worth a shot. Look up "masonry supply <your city name>" on google and give them a buzz!

Whenyou built your little box in the oven did you build it right on the bottom of the oven? Like, did you take out the oven shelves and just build the box? Sounds very interesting. Please give more information regarding the construction of the box.

A comment early in this thread called Granite a sedimentary rock, it isn't. Granite is formed under high temperature and pressure with a very slow cooling time. Most granites don't fracture easily.
Slates are rocks that were once sedimentary shales, that since then have been subjected to additional temperature and pressure; shales tend to break along cleavage planes-where the clays in them were deposited; slates can break along the orginal cleavage of the original shales as well as along secondary cleavage directions tied to the temperature and pressures applied to turn them into slates.
Thus, not all slates are alike and some are much more prone to shattering than others.
Soapstones are often massive but they cut/saw easily because of the fine micas in them. There is also asbestos in some of them.

Generalizations don't work when saying one granite is good and the other not. Likewise slates. Likewise soapstones.

call me a curmudgeon, if you will (others have, by the way), but i've been following this thread for years and i'm just amazed at how much effort folks spend in pursuit of a great baking surface. yes, unglazed tiles work. yes, granite and soapstone work, marble may or may not work, no, slate doesn't work, of which more presently.

but the fact is, there are industrial materials available ... specifically cordierite and fibrament ... that have been have been deemed food safe by the FDA and engineered for high-temp applications. and they, most emphatically, work brilliantly.

one of the things that rarely gets discussed is thermal stability, i.e., what happens when you pour a cup or two of ice water on a stone that's been sitting in a 500F oven for a couple of hours. tile, marble and granite will crack, if not explode (slate will do that on its own, thanks to the air pockets). engineered stones don't crack: they remain stable to temps of 1000F plus for fibrament and 2000F plus for cordierite.

so why all of the running around? is it a matter of economics? yes, a good baking surface will cost more than a stack of tiles, a pile of bricks or a stone remnant at your local floor tile and countertop dealer. yet, folks here will think nothing of spending a couple of hundred (if not more) bucks on a new mixer -- which, by the way, is not a requisite to baking great bread -- while holding back on the extra 30, 40, 50 bucks it will cost to buy a great stone, which IS essential to producing great artisan loaves IMO.

now, admittedly, i'm in the business of selling baking stones, among other things, and i have a financial interest in what people buy and who they buy it from, but that said, a great stone -- whether you buy from me or someone else -- is an investment that's literally going to last several lifetimes (as long as you don't try to bounce it) and will help you bake great bread. plus, all the money you save by baking your own instead of buying (not to mention the nutritional and emotional satisfactions, but that's another story) will more than pay for the extra up front cost of the stone.

it's known as the "Cry once" philosophy...you cry once when you shell out the big bucks for the 'quality' product.

However, the other buyers cry repeatedly, when the inferior product fails, or malfunctions and spoils a job, or needs replacement just when the budget won't stretch far enough to buy another 'cheapie'...<GRIN>

while sometimes you get what you pay for, other times you can get 80-90% of the functionality for 10% of the cost, and for some people its either 10% of the cost, or nothing, and the performance difference is nil, either because they are simply not that picky, or because they are inexperienced enough to not be able to see the difference if they had it.

I have no doubt the fancy modern baking stones perform better and last longer and are more durable, and when I get rich some day, get a fancy oven and so on, I'm sure I'll spend the money to get a high end, fancy stone that will work better than the cheap slab of rock that is far better than nothing, to go in the crappy oven that is my only option at the moment.

is it bizzare that people who could EASILY afford a fancy expensive one, to spend the time and hassle with ultra-budget but ultimately, in the long run, inferior solutions? YES . and I'm sure there are people like that here too.

there are times where its foolish NOT to get the high grade tool. there are others where ANY mostly-functional tool is a huge step up from no tool.

are you REALLY asserting that the new fancy stones make that huge of a difference to the hot-rocks that people have been cooking on for centuries? yes, its better and more durable, but it seems a bit exaggerated that you NEED one of those expensive things to make bread that comes out great.

I would bet that there are many people here who would LOVE to get one of those fancy stones, but simply can't afford it, or do not consider the difference, even if they could make themselves afford it, to be worthwhile. (which, I do not entirely blame them for, <10 bucks for something that works perfectly fine, for now, seems like far less than 50 bucks for good. particularly if you expect to some time between now and "ever" to get a new oven or something that would merit a bigger investment!

and while you may or may not be intending the "for those who can afford it" without saying it outright, IMO it doesn't show through. I might not even doubt that you intend your point towards people who COULD easily afford it, but chose to be penny pinchers. but you don't show that clearly, and your attitude about it has discouraged at least one person who might have bought (that, some day, or other things) from you, from doing so.

I think most regard it bad business to present a bad attitude in association with a store.

my point is simply this ... and i believe i made it in my earlier post ... that all of those other materials will work ... i'm certainly not disputing that, nor am i suggesting that everyone needs to buy a quality stone in order to get great bread.

that said, i am still very much of the opinion that tools matter, and that people who have more than a passing commitment to bread baking -- like anyone who's passionate about a creative pastime -- ought to invest in the best tools they can afford -- no matter where they acquire them. in the case of baking stones, all the more because so many home ovens are "crappy," i.e., they lose heat quickly, heat unevenly and simply aren't designed for the kind of use we demand of them. this debate has been going on for years and i expect it will continue ad infinitum.

as for my attitude discouraging "at least one person" from buying from The New York Bakers, i'm sorry that's the case. perhaps if i refrained from having a point of view and stating it, no one would be discouraged and then i could double or triple my prices to the point where they're comparable to those charged by other sellers of quality bread baking ingredients.

as a baker and a businessman, i sell or recommend only what i believe in and use myself -- at prices that are much more within reach of those on limited budgets. for me, this is less about making money than it is about starting a business aimed at addressing my own and others' frustrations at not being able to find what we all need.

i'm sorry my words have put you off and hope you'll recognize that people will do whatever they choose, and satisfy their own needs in ways that work best for them, regardless of what i or others think.

oh don't get me wrong. I appriciate that tools do matter. I grew up with a dad that did woodworking, some metalworking, and NEVER that I can ever remember, took a family vehicle to a mechanic. he bought Craftsman only tools for everything.

but, and this is sort of to the point Copyu is saying just below, (I think its below... crazy forum program...) if someone is very tight on money, and they need to buy a drill bit for what is most likely a one-time project, or that would do "good enough" for 90% of the projects they are likely to see in the next 5 years, unless they expect some of those projects to appriciate the difference, the buck-fifty drill bit will probably serve perfectly well as the $5-10 carbide one would. it would be SILLY to buy the expensive one. if you aren't really THAT broke, then it might be worth it out of philosophy of using only the best tools, or dignifying the project with quality tools, or whatever. but if thrift is your overwhelming concern...

I *AGREE* that the overall "answer" is that if you are "serious" and you can afford it, that the fancy stones may very well be completely worth it. it may even be worth budgeting to save up for, if you expect to be doing bread baking over the long term, rather than a fleeting hobby.

it is just my opinion that you could have recognized that some people may not find the investment worthwhile, and/or simply not be able to afford it, better than you do.

I'm not saying that I definitely won't buy from you or anything, just sayin that on this point, in my opinion, you could present a more positive representation in this matter.

as i said at the beginning of that post, i've been called a curmudgeon more than once .... diplomacy simply isn't my strong suit (maybe it's my NYC DNA).

i think that we all ought to use the best we can afford -- afford being the operative term here. i also think, germane to your point, that for a baker a stone is hardly an occasional tool. for me, at least, it's something that's always in my oven (they, actually; i have 2) and is my primary baking surface.

i also recognize that finances are always an issue, especially in these tough times, which is one of the reasons i started NYB. i just got tired of paying what i consider exorbitant prices.

The problem that I have is that many of these discussions turn on using tiles and other refractory materials purchased in garden centers, flooring departments, scrap bins, and other sources never intended for food preparation use. Having worked for a number of years for one of the world's largest manufacturers of industrial refractory products I know that industrial refractories often contain, and can leach, materials which you do not want to ingest (or breath as vapors) under any circumstances. And having worked for consumer products companies that sell to big-box stores I also know the tremendous pressure that the suppliers are under to meet the cost targets of the big-box "sourcing specialists".

Do I know for a fact that any of the tiles or "stone" you purchase in a garden center are industrial refractories purchased out of the scrap bin and "repurposed"? No. Do I know for a fact that manufacturers making synthetic stones intended for garden paths are taking shortcuts and using materials that are not exactly safe? No.

Having, as noted, worked for both refractory manufacturers and big-box suppliers to I make damn sure that the ceramics my family uses to cook on are intended for food prep use at high temperature, if possible carry the NSF mark, and if at all possible are made in the US, Canada, or an EU country? Yes, absolutely.

I have WAY too many hobbies and have learned all about quality and value the 'hard way'—through experience. In woodworking, a professional furniture-maker is likely to use certain drill bits almost every working day of his life and his specialties are likely to need only a few sizes. He buys the best ones, individually—he always chooses HSS over Carbon steel, or carbide over HSS, if available. As an amateur, I have no idea what I might be building for my own use, or for friends, over the next few years, so I spend the same money as the pro to buy a full set of the cheapest reasonably-good bits I can find. Many may never be used, but at least there's a tool available to do the job, when it really IS needed. Sometimes, you only need a tool once, or perhaps a dozen times on a single job. After you're finished, you can put that tool in a 'safe place' and it doesn't really matter if you never find it again.

In electronics, you can buy interchangeable audio-amp ICs for $1:40, or $4:95 or $8:50 or $35:00. According to data-sheets and experts, the most expensive ones will sound and perform (perhaps) 5% 'better' than the mid-priced ones and 25-30% better than the cheapest. Which to buy?

good observations. there is a certain satisfaction one can realize in using an inexpensive option that does the job. but as you point out, and several other comments have related, durability is also a consideration. if an ersatz "stone" cracks / breaks up the middle of a baking session, does one assume there's no chunky bits stuck to the bread? or does one assume a broken tooth or two among friends is not really an issue . . . as long as there's an adequate supply of butter?

allowing for space around the edges, I need 22 x 14 inches to make my oven racks "complete"it's a pretty dang standard 30" oven, and I've not found any combination of standard sizes that will fill my oven racks.

I've got a radial arm saw - I've got masonry blades - I can make a lot of dust real fast.what happens if I buy larger size(s) and cut them down? do I introduce stress risers that will cause them to fail/crack/break/explode?

why do the manufacturers not make an assortment of sizes one can mix and match to fit one's oven? for 22x14 I'd _prefer_ it in two pieces - and I don't care if one is 10x14 and the other is 12x14 - I don't need two identical stones 10 and 51.6/64ths by 14 - I need something to line my blinking oven racks!

I used some unglazed tiles for many years for baking pizza and I never had any problems with them. I paid $1.29 for each one at a local Lowe's and the man working in the tile department was very familiar with using tiles for baking.

I still have them and still use them from time to time. I also have two baking stones that I found at a local thrift store for $1.99 each. They still had tags on them and had never been used.

Keep your eyes open and you can get some good deals on the baking stones if you don't want to use the unglazed tiles..actually, the unglazed tiles in some ways were handier than the baking stones, as I could fit four of them in the oven on one shelf and it basically covered the whole shelf. Its very handy for large pizzas or long / large and or multiple loaves of bread.

I was wondering if anyone can advise me. A friend recently gave me one of her baking stones, and I think it is quite old and has been used many times. I dont mind this at all, since I dont have to worry about 'breaking it in'. It doesnt say what brand it is anywhere on it or what it's made out of, but I'm pretty sure it's a commercial baking stone.

Anyway, having been used a lot already the top is darkened by many places where oil has stained it, etc. When I brought it home for the fist time and started preheating the oven with it inside, it started producing a lot of smoke and that burning oil smell. The room was pretty much filled with a smoky haze, actually. The oven hadn't even gotten up over 300 degrees or so when this started to happen.

So my question is: what should I do about this smoking baking stone? Should I just heat it up and let it burn off as much of the stuff on there as possible and hope that eventually all of it will burn off and it will stop smoking?

so,,,, iffin' the pie drips, etc. - that lands on the stone and unless it's heated up to "let's make ashes" from time to time that kind of build up will create smoke on it's next forray into 450-500'F temps.

I'd just set the oven as high as it'll go and let 'er rip. helps if you can pick a day when you open the windows . . . .[g]

That's exactly what I do..sometimes I have a messy pizza and when the pizza is out of the oven or the next nice day, I heat the oven up to 500 with the messy stone and let it smoke and burn. I have set the smoke detectors off once or twice even with the fans on, etc.

I do get any pieces of cheese or crust off the stone before I do this..I don't use it to burn up large "globs' of stuff, just the occasional grease or whatever that kind of soaks into the stone.

As a consumer, there are few assurances that the materials produced for a non food application are safe for contact with food. I haven't heard any reports that unglazed quarry tiles are unsafe for cooking on. They could be but I haven't ever heard of a single instance where the family was poisoned by clay tiles.

Tiles don't have much thermal mass anyway. From a performance standpoint, I would say if you don't want to spend for a high value stone like NY Bakers sells, get yourself a stack of parchment paper and bake on a sheet pan.

I'd also like to see what the famous 'quarry tiles', etc, look like...I knew what that meant in 'Australian English' when I lived in Australia. (I never even wondered whether Americans or Brits might have a different name for that same product!)

However, I live in another part of the world now...most of the stuff in hardware stores is imported, but they "localize" the names of the goods for sale and they don't always mention the country of origin. It can be very confusing.

Brick-clay tiles...unglazed earthenware tiles...that's what 'quarry tiles' were, where I lived before. There were various sizes and finishes, though. Some had a polished surface, with very few 'inclusions' and were often used indoors; about 10-12" was a popular size for 'hacienda'-style homes.They required a fair bit of 'finishing' by the builder or homeowner after being laid.

Outdoors, the 6" were occasionally used on patios (but most people [DIYers, anyway] used 'solid brick' pavers...I seem to remember that pavers were a bit harder to lay flat, but worked out a bit cheaper...maybe because they saved concrete?)

This photo could be of my own quarry tiles. They are exactly like this. A couple of names I've seen these as are UNGLAZED saltillo, ceramic, terracotta, and quarry. The most important thing is that they are UNGLAZED.

I bought a whole box of them, I think I paid $24 in case any of them break. I do leave them in the oven all the time (not the box, just the ones I'm using :-P ).

My trouble is that I would like to find a 3rd oven rack so I can try some different configurations and don't have to move the rack with the tiles so much. I also use the iron-skillet on the last shelf with boiling water method for steaming. Someday I'll get a large terracotta flower pot and make a cloche for the bread to self-steam. They should be coming out with those things now that the weather is turning here.

I am a newbie in bread baking and I’ve learned a lot from all of you guys here, thank you very much Now I’m investing in my first automatic gas oven and I have a few questions about baking stone…1. I’m hesitating in paying so much for the commercial baking stone and wondering if the unglazed quarry tiles will do the same job??I’ve seen some people use 2 layers of tiles, what’s the purpose in stacking them up?2. Is the thickness of the tile matter, I’ve heard that you should look for 3/4 – 1″ thick for durability…3. Would steaming your oven with garden mister make the tile crack or explode?

Quarry tiles are just a hewn and shaped piece of stone. as it is intended to go on the floor, the weight of a loaf is not going to distress it too much.

All other tiles are fired, teracota, ceramic, wall, floor. They can ALL be used to provide solid, sustained heat to emulate a commercial bread oven to give great even colour and crust formation. Have tried glazed, unglazed, teracota and stone

Put heavy, uneven weight on one suddenly and you will eventually break it. Heat it up very, quickly and or unevenly, once again you are asking for trouble. Cool them down very rapidly and or unevenely, youre running a risk.

I use a slab of granite right now, works a treat. Granite a health risk? get in touch with reality. Some cities have Thoousands and thousands of tons of the stuff in buildings. How bothered about naked gas flames in your kitchcen? The chemical vapour coming from hot oil? Ever walked down a busy street or been stuck in traffic? Whats the distinctive smell at the fuel station every time you go to fill your car?

Find something that works for you and use it. Enjoy making wonderful bread and home baked goods. The contented, happy feel good chemicals your body will release will do plenty to keep you healthy and live a bit longer.

Go bake and prosper.

From a time served baker who has never tired of pulling loaves from an oven

Below are pics of the quarry tiles I have been using. I only have two oven racks and have lined both of them. I leave them in all of the time (too lazy to remove them) but that is at a cost of longer preheating times.

The thing is I live in Thailand where good bread is almost impossible to find, that’s the reason I start baking my own bread and now even thinking of selling them to the local store. And because there’re so few of a professional bread baker, the supply of good oven suitable for baking bread is even more impossible…

After a long search, I’ve decided on a 4 tray/ automatic gas oven from a local supplier. It’ll cost me around $ 1,500, and $ 150 more to line the bottom of the oven with baking stone…The oven will look somewhat like the one in this link, but a 4 tray instead of 2.http://bakeryeasy.net/detail%20spec1/002gas%20auto%20oven.html

My problem now as you can see is the chamber of the oven is only 22 cm high and have no shelf!If I line it with tiles at the bottom and bake my bread on it, I have no shelf or extra space to place a broiler tray or iron skillet to pour water and create the steam. The only way for steam is through a garden mister and I don’t know if it’s safe for the tile since that it’s very likely there’ll be a direct contact of water and tiles.

Should I even bother searching for quarry tiles or should I just pay $150 for the baking stone?Or they both will break anyway from the steam and I should use the tiles since it’s cheaper?

Any creative ideas on modifying my oven to be more professional? I appreciate any suggestions.

Is this oven only to be used to bake flatter breads? The small space inside seems like it could be very confining for a good amount of money. I wasn't sure what your goal was. Is it to be able to heat up hotter than the one you currently have?

I'm sorry that I don't read Thai or I would be able to better understand what features this oven offers that you want. Whether it "looks" professional or not, does not necessarily matter. All that matters is that you get what you need to do the type of baking you want to do. That is a lot of money (if you are talking USD) for a small oven, so I am not certain where those types of oven fall in the overall schemes of cooking appliances where you are.

So, I would make sure that you are getting what you want that can be as flexible as you want it to be and it can do what you want it to do with minimal "drama".

This oven is actually not small since it is 1x1.5 meter in size and can fit 4 trays (40x60 cm), but I agree with you that the space inside the chamber is quite small :-(

This type of oven is used here for bakery production, either it's cake cookie or bread. I intend to use them for all types of bread, not just flat bread, but now that you mention I'm quite concern about the hight of chamber. Would it burn the top of a big loaf given that the chamber is only 22 cm?

I never have experience with gas oven before and have always used the electrical ones. This will be my first gas oven and quite a big investment so I'm quite worried.

If you can subject ordinary slate tile to a gas burner on a stove top, cook a fish on it, and eat it without fear of explosions or industrial contamination, I suppose (and this is just a guess, mind you) that baking bread on slate and then eating it is also safely doable?

so i'd perform some due diligence before i go out and get some flagstones for my oven. i don't care much for Martha, since i don't really trust anyone who likes to cook while staring the camera in the face rather than focusing on the actual cooking, but that's just me.

seriously though, there's so much variation in the kinds of slates, shales, quartzites, bluestones, etc., out there, that without a pretty detailed evaluation of what you're getting, you could be in store for some upleasant surprises. naturally occurring is great, as long as you've taken appropriate precautions. that's one of the reasons i like synthetics -- you always know what you're getting (unless it's from Enron).

Slate is usually pretty plain stuff. Slate is slate. Rocks and stones can be just about anything geological, but not slate. Unless it's not slate. But why call something slate if it's not? If you can't trust a place that sells slate because it's actually something else, well then you might as well forget the whole thing and just say "only geologists need apply."

I bought some plain, ordinary, rough-hewn, bluish-grey slate tiles (matching them for equal thickness) at a Home Depot recently, washed them with dishwasher detergent and rinsed them off nine times to make sure the soap was gone. Next, I let them air dry in a fairly low humidity area for five hours. Finally, I placed them (4 6x6" slates and 7 4x4" slates) in a 16x16 configuration on the lowest rack of my oven. 20 minutes at 150 F., 20 minutes at 200 F., 20 minutes at 250 F., 20 minutes at 300 F., 20 minutes at 350 F., 20 minutes at 400 F., 20 minutes at 450 F., and 20 minutes at 500 F., with a separate oven thermometer measuring the actual surface temperature of the slate in conjunction with the oven's temperature dial. The dial selection remained constantly 25 degrees lower than the average slate surface temperature.

After 40 minutes, the few mild aromas that came off the stones as they heated up dissipated and all that was left up to 500 F. was a clean, gentle heat.

Got some great baguettes and boules off that surface.

Cordierite, on the other hand, is composed of a good amount of aluminum (not something I want leaching into my bread crusts).

How many times in the above list of minerals that are found in clay can we find the letters that stand for the element aluminum (Al)? Hmm?

I'd gladly trade in the very inexpensive slate tiles for something else that is as pure as slate and has no aluminum component. Something else other than cast iron, that is.

Anyone know of anything available, anywhere at any price, that fits that description? Cause if you do, I might just trade it in for the slate. But remember, Fibrament doesn't count. The company won't tell anyone what the heck the components of that little gem are.

i will point out, however, that the chemical composition you gave for cordierite is in its naturally occurring mineral form. most synthetic cordierites are manufactured without aluminum precisely because there are questions about its long-term effects.

Are you willing to risk your health and the health of your family and friends on what the FDA approves and does not approve? I am not.

The FDA is not a Supreme Being with the power of life and death. It is a division of the United States government composed of people, none of whom are infallible. Information from the FDA should be used as a basis for further investigation, not for a final judgement.

I have to wonder why you're so paranoid about aluminum. The health risks touted appear to be the result of a backward reasoning, i.e. Alzheimer's sufferers have excess Al in their brains, therefor one must avoid ingesting Al. Trials that seemed to have supported the hypothesis were all found to be poorly structured. Other trials that were well constructed found no correlation.

This reminds me of the high serum cholesterol is caused by eating saturated fats irrational thinking, and too much dietary calcium causes calcium deposits in the joints.

In the first case, clinical trials have repeatedly found dietary fats to have an insignificant effect on serum cholesterol. More likely, from the evidence, is that low dietary anti-oxidants cause increased cholesterol production by the liver, cholesterol being an anti-oxidant, itself. Vegans tend to have lower cholesterol levels, but that is better explained by the diet being high in anti-oxidants. Blaming dietary cholesterol does not explain vegans with high serum levels.

For years, doctors were advising diets low in dairy and other calcium sources for people suffering calcium deposits in their joints. Then they discovered these people were suffering from osteoporosis from lack of calcium, and that the original deposits were the body's way of conserving what calcium it had. (Just as the body conserves fat and burns muscle during fasts.) Turns out the proper treatment was to increase calcium intake.

This is not to denigrate your concerns. It's just that our news sources depend on the latest scare, and seldom (ever?) come back with, "Remember when we said you were gonna die? Never mind."

Don't stop being concerned, but do seek out contrary views, and study the evidence (real evidence, not anecdotal or "studies" designed from the git-go to prove a viewpoint) for both sides. Neither side has a lock on being right, but judicious study on your part will lead to a more rational understanding of the risks in general, and to you and yours in particular.

And, back to the excess of aluminum in the brain; isn't it possible, in light of the calcium and cholesterol findings, that the body has some as yet unknown reason for routing this trace element there? Consider that nearly all of us are exposed to and ingest aluminum all our lives, yet only about one in eighty-five of us succumb to Alzheimer's. Were I the researcher, I'd spend my time seeking the cause of the high concentrations, or why the body isn't ridding itself of the excess first.

However, I would not characterize my discomfort with aluminum as an instance of paranoia. True. I do avoid aluminum in my food preparation materials. However, if I go to a restaurant, I do not ask to inspect the kitchen for aluminum pots and pans. I just avoid restaurant dining when there is no special occasion for it.

If it turns out, decades from now, that scientists prove aluminum has no ill effects on the human body, I will not be disappointed. But look at the flip side. What if aluminum does create a problem? As we currently do not know the answer, is it not sound advice to avoid aluminum wherever we can? What's the harm in using inert silicone products that have no link to health issues? Why risk what is not necessary? Especially when I will most certainly be subjected to it on those special occasions mentioned above (as it is less expensive, aluminum utensils are probably what most restaurant kitchens have available for their chefs).

It is not that I am paranoid about aluminum. It is merely that I see no reason to risk using it myself when there are safe alternatives. Stainless steel pots and pans come to mind.

It is not my intention to prove that aluminum is bad for the human body, as it may well not be. But again, I say, what is the problem with avoiding it as much as possible? It is not a person. It has no feelings. It will not become angry with me or get insulted if I avoid it. So I will continue to avoid aluminum to the best of my ability.

Caution is a good thing.

Palau

P.S. - As far as the clinical studies go, what if some of us have some unknown epigenome in us that predisposes us to getting Alzheimer's disease when subjected to food prepared in aluminum utensils?

That scenario would not play out well with the studies that have thus far been conducted. Scientists would have to have, on file, every epigenome in every human being on this planet before even starting the study. A gargantuan task I believe they will not soon undertake. ..........................................................................................................................

If people are keen to investigate tiles rather than baking stones it might be worth looking into oven grade fire bricks of the type used to line the floors of wood burning ovens, that is if your oven can take the weight of them which can be 8lb per brick. You won't find them down the garden centre in the UK - you would need to go to one of the specialist suppliers listed online. Posts in oven building forums suggest they are more widely available in masonry stores in the US, less widely available in Australia.

There are different grades - those for woodburning hearth stoves are not recommended for baking, furnace grade may be too high. Those for woodburning ovens are used for baking floors and are designed to withstand thermal shock. These are sometimes described as 'medium grade'. They cost upwards of £1.50/$1.20 per brick (although prices seem to vary widely) and can come in larger sizes.

There is a very interesting primer on the Forno Bravo woodburning oven forum on using fire bricka, clay and concrete on oven floors and some interesting discussions on sourcing fire bricks in the materials section http://www.fornobravo.com/pompeii_oven/brick_primer.html and http://www.fornobravo.com/forum/f44/. Unfortunately clay/terracotta comes out as cheap but likely to crack and a relatively poor conductor of heat. Fire bricks have alumina in them and this has been raised as a concern earlier in this thread, however any aluminium in the brick should be extracted in the production process. As non-food-safe clays will contain whatever the original soil contains they could contain arsenic as this is widespread (British Geological Survey recently found it is 28,000 sites around Britain). For tiles then maybe it's a case of 'choose your poison'? Some woodfired bakeries bake on fire brick. However the brick lining woodburning hearth stoves are certainly not recommended. As for me I think I'll get a stone if I can find one to fit my small oven.

Anyway - happy and safe baking everyone - may your bread rise to meet you and your stone never blow up etc! Daisy_A

Actually, there has been quite an ongoing controversy about granite having radon gas emmisions. If you do a Google search on "granite and radon", you will find that CBS and the Early Show have featured this concern. I had been researching this before deciding what to use on my kitchen counters (it WONT be granite). That being said, granite would not be a good item to bake bread on.

As I posted elsewhere here on TFL, I made mine out of thin builders bricks. Since I am in the Philippines, it is impossible to ascertain their composition or that they are completely food safe. Thusly, I never place food or dough directly on them, but rather use a pan, foil or baking parchment inbetween the bricks and the food.

They have done a superb job of evening the temperature out in my oven, which was very problematic before. I had a very hard time maintianing a set temperature. Now, I have a much easier time getting a good even temperature that stays even if I have to open the door to put food in or check its progress.

I had handles added to mine, but I am going to have a second made without handles so I can set larger baking sheets on it without a problem.

I'm not talking about trace amounts either, it's FULL of LEAD. DON'T EVEN THINK OF USING IT.

Unglazed floor tile is basically just fired clay. It's perfectly OK. As a matter of fact, many people greatly prefer unglazed terra cotta for pizza stones over the store bought ones or anything else.

A few more tips that I have learned about using terra cotta tile as a pizza stone:

Before you use it, season it with a few layers of olive or vegetable oil. The tile is porous (has thousands of little microscopic holes in it) and will literally soak it up. After these little holes are evenly soaked in oil, they distrubite heat evenly. If you don't season it before using it, the little oil spots which will eventually occur from cooking things like will pizza, will create hot spots on your stone and end up cracking it.

Of course, never put cold water on a hot stone, this will crack it for sure.

Also, heating up your stone too fast, will do a good job cracking it too.

Just as with a cast iron skillet, never EVER use soap on your stone. Those little pores that I was talking about earlier, will soak it up and mix with the oil, ruining your nicely seasoned stone.

The more you cook with a well seasoned stone, the better it gets. The taste is amazing and your crusts will get nice and flakey. It cooks more evenly and your pies will have a much harder time sticking.

* First, while it is true that most imported glazed tiles contain lead, all U.S. ceramics manufacturers were required to stop using lead in 1978.

Also, lead may or may not pose a health hazard in ceramic glazes, depending on the type of glaze and the firing temp. At high firing temperatures, such as for porcelain, the lead binds to the glaze, making it biounavailable. Porcelain tiles are glazed at anywhere between 2000F/1100C and 2500F/1400C -- far higher than any home oven is likely to go.

As a practical matter, unless you're using terra cotta tiles imported from, say, Mexico, which are fired at low temps, and other similar tiles, the likelihood of lead toxicity is very low.

* Second, terra cotta is too broad a term, since what's sold as terra cotta can range from cool-fired, large-grained clays, such as Mexican saltillo tiles, to hot-fired fine-grained clays, as in the dark red Italian quarry tiles. Obviously, the higher the firing temp, the more stable the material, and the less likely it will be to have hidden cracks, fissures and bubbles that are largely the cause of cracking.

* Third, NEVER oil your stone. What's the point? Stones cook breads by vaporizing the moisture in the bottom crust: for the first several seconds, the dough actually floats above the stone on a microscopic layer of steam, while the high heat of the stone forms the hard crust, which diesn't adhere to the stone once the bottom moisture vaporizes.

Baking heat will turn the oil into varnish and the stone will give off a strong, unpleasant smell for a long time after. Soak the stone with oil and you'll never get it out. Best way to ruin a stone is to oil it. If you do end up getting grease spots from pizza, etc., just run the stone through your oven's self-clean cycle and they'll vaporize into light gray ash, no harm done.

* Fourth, cold water won't necessarily crack a hot stone; materials vary in their ability to resist thermal shock, i.e., cracking when they encounter cold. Some materials, like tile, terra cotta and many natural stones are inherently unstable and will, indeed, crack if doused with cold water. Certain man-made materials, like FibraMent and cordierite have far greater resistance to thermal shock. Cordierite in particular is stable to temps in excess of 2000F. I use two cordierite stones and routinely douse them when I steam my breads. I've had the stones for over 10 years and never had any kind of cracking problem.

* Fifth, heating "too fast" is meaningless. What's too fast? How do you measure it? Again, thermal stability depends entirely on the material and how it was manufactured. Some materials that have higher heat conductivity (thermal efficiency) may end up vaporizing trapped moisture, which could fracture the stone, but again, there's no hard and fast rule.

* Sixth, I agree with you that soap or detergent is a no-no. You finally got one right.

*Seventh and last, "seasoning" is meaningless, since, as noted above, a stone bakes the bottom crust by floating it on a microscopic layer of steam and forming the crust before actual contact is made. Neither a stone's thermal efficiency nor its resistance to thermal shock increases over time, nor does a collection of food residue impart anything resembling a desirable flavor.

If you're going to pontificate on stones, at least know what you're talking about. A lot of people here depend on this site for good, dependable information, and you're not doing them any favors by posting bad information.

Both are made in the US and I couldn't tell any difference - love the results from both. Only difference is the flower pot saucer has a lip and is round and for most projects I think I prefer the flat square stone. With the saucer I did keep all of the corn meal inside instead of brushing some off into my oven. I imagine I could flip the saucer upside down if I didn't want to deal with getting my boules over the lip.

Both are about 1/2" to 5/8" thick. Anyhow, if you want to try using a baking stone for the first time and have a home depot handy you can try the saucer and see the difference it makes in your bread. I think it was $15 and is a lot better than the really thin pizza stones sold at Target or other discount stores.

My wish is that I hadn't wasted so much time reading all the other discussions about these issues, finally someone who is thinking these things through before they post thank you nybaker. The only thing that I would add is that the as far as ceramic materials used is that elements like lead are used as colorants in ceramics so generally in glazes and then used only in low temperature glazes because they would burn off in high temperature glazes. Low temperature in the world of ceramics though is like the guy said over 1000 F. Iron is usually the main colorant in terracotta (low fired clay) with a chance that they may be throwing in a small amount of lead to bring color more in the red range rather than brown. The real question would be if the tile leaches lead, the answer is that many ceramics you probably have in your kitchen now are leaching some lead, which will probably horrify people who didn't already know this. It doesn't mean they are not rated food safe. The food safe rating considers an acceptable level of leaching. Clays themselves are different colors when fired because of the elements in the clay, which is why the one tile was gray in the middle they sandwiched a gray clay and wrapped it with the red clay to stretch the red probably colored clay. They range from red clays all the way to pure white porcelain. Porcelain clays are usually high fire clays cone 10 and above. The cone rating is a function of temperature and time, so in the firing process cone temperature means you get the temperature and stay there for a specific amount of time. Cone 10 is around 2300 F. I use a kiln shelf for my baking stone it's rated to cone 10 and most likely the only way I'm going to crack it is if I decide to pitch out my back door because it's ability to withstand thermal shock is far above the temperatures I can generate in my oven.

Now I'm sure that is more than you ever wanted to know especially about ceramics so please excuse my rant, I too willl step off the soap box now.

I realize I'm jumping in kind of late here, but I know of at least one pizzeria whose oven deck contains asbestos. Asbestos is actually pretty safe to use as long as the particles aren't coming loose. And it's great for high-heat applications. So while I doubt you're going to find a pizza stone containing asbestos, as long as it's not friable it should be perfectly safe.

As per the post above.....I got my 1.5" thick granite baking stone for free from a local supplier of granite kitchen worktops. Turns out, they have loads of offcuts from making the worktops and they were happy to cut it to the exact size to fit my oven and then bevel the edges. They wouldn't take any money for it either - seemed to just be happy to show off their expensive CNC saws.

Anyway - it works great for me. I just leave it an hour to heat up fully in the oven and then slide the dough onto it. Good oven spring and good crust. It's also good for an initial steam as well - I just spray some water onto it just prior to sliding the dough in. In fact, it just lives in the oven these days - the extra thermal mass seems to work well for most types of cooking.

I just put 6 of the unglazed tiles (same as in the first picture in this post) on a sheet pan and stick them in the oven. Works great. Looked up a construction store which sold tiles and such and went in. As soon as I asked if they had unglazed quarry stones I could use for baking they knew exactly what I was looking for.

Regards, Tom C

PS During my search people often paid $.50 each. I paid $1.00 each. So, I'm out $12.00 for my total purchase. Usually I only use 6.

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